Bilateral Keratoconus in Diffuse Cutaneous Systemic Sclerosis: A Rare Presentation - Is There Any Role of Autoimmunity?

Keratoconus (KC) has long been defined as a noninflammatory disease of the cornea.However, recent evidence increasingly suggests the possibility of an underlying subclinical inflammation that may contribute to KC pathogenesis. 1,2Studies have linked KC to various systemic illnesses such as allergy, atopy, collagen vascular diseases, and autoimmune diseases like ulcerative colitis, rheumatoid arthritis, and Hashimoto's thyroiditis. 1,2Systemic sclerosis (SSc) or scleroderma is a chronic multi-system autoimmune connective tissue disorder that primarily affects the skin. 3Ocular involvement is mostly in the form of eyelid abnormalities, dry eye, and retinal and choroidal vasculopathy. 4In the literature, there are a few solitary reports of KC in SSc. 5,6,7Here we present two cases of bilateral KC associated with the diffuse cutaneous type of SSc.Case 1: A 24-year-old Asian female with a history of SSc (anti-SCL70+) diagnosed 2 years earlier presented with complaints of worsening vision in both eyes for 6 months.She was on oral corticosteroids and immunosuppressives that included oral hydroxychloroquine sulfate 200 mg once daily (IPCA Laboratories Ltd., Mumbai, India), mycophenolate mofetil 500 mg twice daily (Panacea Biotec Ltd., New Delhi, India), and nifedipine 20 mg once daily (Cipla Ltd., Mumbai, India) for the last 2 years.There was no history of parental consanguinity, family history of KC, or personal history of chronic eye rubbing, allergic eye disease, atopic disease, or any other systemic diseases.Physical examination revealed generalized skin tightening, taut eyelid skin, and puffy pale fingers suggestive of Raynaud's phenomenon (Figure 1A).The best corrected Snellen's visual acuity (BCVA) was 6/6 in both eyes.Slit-lamp examination showed an incomplete Fleischer's ring (Figures 1B andC) and corneal tomography revealed an inferior cone in both eyes (Figures 1D andE).Dry eye investigations and ocular surface staining were normal.Fundus examination was also normal.Based on the tomographic findings, a diagnosis of stage 1